Several investigators have implicated modified ribonucleosides presumably modification products from transfer ribonucleic acids (tRNA's) as potential biological markers for cancer. Elevated levels of these molecules have been quantitated in the serum or urine of cancer patients by HPLCUV or immunoassay. In this proposal we will demonstrate the feasability of preparation of antibodies to two common modified nucleosides and the development of an immunoassay for their easy quantitation. Additionally, the levels of 30 modified nucleosides will be determined in the serum from lung cancer patients and normal controls. These data will be subjected to pattern recognition analysis to develop a profile of selected serum modified nucleoside concentrations which can define a biological marker(s) for lung cancer. An immunoassay diagnostic kit will be developed for detection of these biomarkers with attributes of high sensitivity and specificity.